• Advances in environmental research
• /
• v.9 no.1
• /
• pp.65-84
• /
• 2020

The potential use of Sargassum boveanum algae for the removal of uranium from aqueous solution has been studied by varying three independent parameters (pH, initial uranium ion concentration, S. boveanum dosage) using a central composite design (CCD) under response surface methodology (RSM). Batch mode experiments were performed in 20 experimental runs to determine the maximum metal adsorption capacity. In CCD design, the quantitative relationship between different levels of these parameters and heavy metal uptake (q) were used to work out the optimized levels of these parameters. The analysis of variance (ANOVA) of the proposed quadratic model revealed that this model was highly significant (R² = 0.9940). The best set required 2.81 as initial pH(on the base of design of experiments method), 1.01 g/L S. boveanum and 418.92 mg/L uranium ion concentration within 180 min of contact time to show an optimum uranium uptake of 255 mg/g biomass. The biosorption process was also evaluated by Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherm models represented that the experimental data fitted to the Langmuir isotherm model of a suitable degree and showed the maximum uptake capacity of 500 mg/g. FTIR and scanning electron microscopy were used to characterize the biosorbent and implied that the functional groups (carboxyl, sulfate, carbonyl and amine) were responsible for the biosorption of uranium from aqueous solution. In conclusion, the present study showed that S. boveanum could be a promising biosorbent for the removal of uranium pollutants from aqueous solutions.

• Asian-Australasian Journal of Animal Sciences
• /
• v.20 no.5
• /
• pp.706-710
• /
• 2007

This study was to investigate the caponization effects on bone characteristics in male chickens, and the optimum testosterone implantation dosage on bone characteristics improvement. Healthy Single Comb White Leghorn cockerels were caponized at 12-wk-old and selected at 16-wk-old for a 10-wk feeding experiment. Fifteen intact male and caponized male chickens (capon) respectively were assigned to trial 1. Ten sham-operated chickens and 40 capons (randomly allocated into four treatments) were implanted with cholesterol (1.62 mm i.d., 3.16 mm o.d., $9.24{\pm}0.36$ mg), low (1 mm i.d., 3 mm o.d., $5.88{\pm}0.23$ mg), medium (1.62 mm i.d., 3.16 mm o.d., $9.81{\pm}0.17$ mg) or high dose (2 mm i.d., 4 mm o.d., $16.7{\pm}0.24$ mg) of testosterone in trial 2. The results from trial 1 showed that the tibia length, relative tibia weight, breaking strength, bending moment and stress in intact males were higher than capons (p<0.05). The blood phosphorus concentration in capons was higher than the intact male chickens (p<0.05). Caponization also resulted in more antrums and osteoclasts within periosteum and cortical bone from histological observation. In trial 2, the adverse impact of caponization on the bone breaking strength, bending moment and stress could be alleviated through medium dose testosterone implantation. It appears that caponization reduced androgen secretion hence influenced the biomechanical characteristics of bone (tibia) and these adverse effects could be alleviated through appropriate dose of testosterone implantation.

• Resources Recycling
• /
• v.20 no.6
• /
• pp.28-36
• /
• 2011

The adsorption of nickel(Ni) from sulfuric acid solution was carried out by ion exchange method. A series of batch tests in synthetic solutions were carried out using Lewatit Monoplus TP 220 resin. The following experimental parameters, such as temperature, shaking rate, reaction time, pH, resin dosage and concentration of nickel ions etc. were investigated to establish the effective optimum conditions of nickel adsorption. The solution pH(2.0~5.0) and shaking rate had little effects on the adsorption of nickel and adsorption time of 72hours was required to reach equilibrium. The experimental results show a good agreement with Feundlich isotherm and pseudo-second order reaction. The adsorption behavior of Ni obtained from synthetic solution was compared with that of waste electroplating solution. Elution of nickel from loaded resin increased with increase in $H_2SO_4$ concentration.

• Journal of Convergence for Information Technology
• /
• v.10 no.10
• /
• pp.135-142
• /
• 2020

In the recent farming industry, there is a growing diffusion of drones, which are recognized as a crucial technology of the 4 th industrial revolution to cope with aging. Especially, filming and pest control using drones are representative fields that have different age groups for obtaining a national license of multicopter that is a ultra-light flying device, and can create profits after getting a license. However, pest control technology using drones has different spray effects depending on levels of operational proficiency, since this highly relies on an operator's operating skills. It is anticipated that if this issue is supplemented, the use of drones for pest control in the farming industry will diversify. For analysis of spraying characteristics of agricultural pest control drones, this study aims to formulate effective spraying hours and effective spraying intervals and suggest an algorithm, which facilitates an accurate calculation of pest control area depending on the kinds of pest control drones. This algorithm can be used in the field of pest control by improving scatterling issues caused by drone flight methods of drone pest controllers and building an optimum pest control manual in future.

• Journal of Environmental Science International
• /
• v.17 no.9
• /
• pp.1023-1032
• /
• 2008

The feasibility study of the application of the photoelectrocatalytic and electrolytic/UV decolorization of Rhodamine B (RhB) was investigated in the photoelectrocatalytic and electrolytic/UV process with $TiO_2$ photoelectrode and DSA (dimensionally stable anode) electrode. Three types of $TiO_2$ photoelectrode were used. Thermal oxidation electrode (Th-$TiO_2$) was made by oxidation of titanium metal sheet; sol-gel electrode (5G-$TiO_2$) and powder electrode (P-$TiO_2$) were made by coating and then heating a layer of titania sol-gel and slurry $TiO_2$ on titanium sheet. DSA electrodes were Ti and Ru/Ti electrode. The relative performance for RhB decolorization of each of the photoelecoodes and DSA electrodes is: Ru/Ti > Ti > SG-$TiO_2$ > Th-$TiO_2$. It was observed that photoelectrocatalytic decolorization of RhB is similar to the sum of the photocatalytic and electrolytic decolorization. Therefore the synergetic effect was not showed in pthotoelectrocatalytic reaction. $Na_{2}SO_{4}$ and NaCl showed different decolorization effect between pthotoelectrocatalytic and electrolytic/UV reaction. In the presence of the NaCl, RhB decolorization of Ru/Ti DSA electrode was higher than that of the other photoelectrode and Ti electrode. Optimum current, NaCl dosage and UV lamp power of the electrolytic/UV process (using Ru/Ti electrode) were 0.75 A, 0.5 g/L and 16 W, respectively.

• Applied Chemistry for Engineering
• /
• v.10 no.4
• /
• pp.592-598
• /
• 1999

Exterior finishing materials of artificial stones are manufactured with the mixture of water, cement, stone powder and light-weight aggregate. In this research, we tried to find a way of increasing the physical properties and decreasing the manufacturing cost of artificial stone. So, we used ${\beta}$-NSF base surfactant and vinsol base surfactant to the artificial stone mixture instead of light-weight aggregate. The optimum dosage of the ${\beta}$-NSF and vinsol surfactants for artificial stone are found to be 1.0 wt % of cement, respectively. The physical properties increased ca. 20% and the durability for freezing & thawing of the new artificial stone increased ca. 300%. While the manufacturing cost of the new artificial stone decreased as much as 30%.

• Journal of Korean Society of Water and Wastewater
• /
• v.31 no.2
• /
• pp.177-186
• /
• 2017

This study concerned the analysis on the efficiency of the conversion of water tank type supply system to direct water supply system to examine the feasibility of the conversion, as well as the calculation of optimal conversion range that enables the supply of safe, high-quality water at stable pressure in accordance with the standards of water supply facility. The results of this research showed that when converting water supply system from water tank type supply system to direct water supply system, more nodal points could be properly converted and more reduction of electricity usage was expected in case water pressure rather than residence time was fixed. This means that higher efficacy can be obtained by fixing water pressure when converting water supply system. However, since the number of the locations that received on-spot inspection was small and the electricity usage measured was not exclusively by water supply facility, it is difficult to judge that such reduction of electricity usage accurately represents reduced electricity usage by water supply facility alone. therefore, after having secured on-spot information about a larger number of locations in apartment complexes that have converted water supply system, and utilizing information about electricity usage exclusively by water supply facility, the proposed method of this research could be applied to accurately deducing expected reduction of electricity usage by water supply facilities of various other apartment complexes. It is also considered possible to deduce an effective operation method of water supply system by finding out an area that shows low pressure or low residual chlorine concentration in the optimal conversion range of water supply, followed by estimating the proper location of pumping station or the proper chlorine dosage at the power purification plant that supply water to the target area.

• Asian-Australasian Journal of Animal Sciences
• /
• v.15 no.8
• /
• pp.1170-1177
• /
• 2002

An experiment was conducted to assess the interaction between genotypes and dietary lysine content in commercial broiler chicks by measuring growth, and response to sheep red blood cells (SRBC) and Escherichia coli (E.coli) inoculation. Female chicks from four genotypes (A=Anak 2000; B=Hubbard; C=Cobb and D=Synthetic broiler) were fed four levels of lysine in diet from d old till the end of experiment. The lysine content of the diet was 9.61, 10.51, 11.41 and 12.31 g/kg. Body weights at 0, 14, 28 and 42 d of age and pen-wise feed intake till 14, 28 and 42 d of age were recorded. Production of antibody against SRBC and resistance to E.coli were measured at 5 d of post inoculation (PI) at 43 d of age. Also, response to phytohemaglutinin-P (PHA-P) was measured at 12 and 24 h of PI at 48 d of age. Genotype by dietary lysine interaction was significant for body weights at 14 and 28 d of age, but not at 42 d of age. Genotype by dietary lysine interaction was not significant for feed efficiency, for antibody titers against SRBC, and for air sac lesion score, relative bodyweight change, and relative weights of bursa and spleen in response to E.coli inoculation. However, a significant interaction was observed between the levels of lysine and dosage of SRBC for antibody titers. There was significant genotype by dietary lysine interaction for cutaneous basophilic hypersensitivity (CBH) response to PHA-P at 12 and 24 h of PI. It may be concluded that to obtain optimum body weight and immunity in commercial broilers the dietary lysine requirement may be recommended specific to the genotype.

• Journal of Korean Society of Environmental Engineers
• /
• v.27 no.8
• /
• pp.837-843
• /
• 2005

Coagulation influence was evaluated as the pretreatment for ultrafiltration. Coagulation was expected to improve water quality, reduce membrane fouling and increase backwash effect. Continuous operation of UF was employed in order to investigate the influence of coagulation. Alum, PACS and Ferric chloride were used as coagulants separately. From the result of the research, coagulation can improve the treated water quality greatly. Organic removal was increased more than turbidity and showed an improvement of 30.6% at most. All three coagulants presented conspicuous reduction of membrane fouling, among which PACS was the most effective with long term run. Backwash effect differed with different coagulants while Ferric chloride turned out to be the most effective one. The optimum dosage of coagulant resulted in the highest backwash efficiency.

• International Journal of Highway Engineering
• /
• v.15 no.4
• /
• pp.107-116
• /
• 2013

PURPOSES: The liquid-type chemical warm-mix asphalt (WMA) additive has been developed. This study evaluates the basic properties of the additive and the mechanical properties of WMA asphalt and mixture manufactured by using the newly developed chemical additive. METHODS: First, the newly developed WMA additive was applied to the original asphalt by various composition of additive components and dosage ratio of additive. These WMA asphalt binders were evaluated in terms of penetration, softening point, rotational viscosity, and PG grade. Based on the binder test results, one best candidate was chosen to apply to the mixture and then the mechanical properties of WMA mixture were evaluated for moisture susceptibility, dynamic modulus, and rutting and fatigue resistance. RESULTS : According to the binder test, WMA asphalt binders showed the similar properties to the original asphalt binder except the penetraion index of WMA additive was a little higher than original binder. From the Superpave mix design, the optimum asphalt content and volumetric properties of WMA mixture were almost the same with those of hot mix asphalt (HMA) mixture even though the production and compaction temperatures were $30^{\circ}C$ lower for the WMA mixture. From the first set of performance evaluation, it was found that the WMA mixture would have some problem in moisture susceptibility. The additive was modified to improve the resistance to moisture and the second set of performance evaluation showed that the WMA mixture with modified chemical additive would have the similar performance to HMA mixture. CONCLUSIONS : Based on the various laboratory tests, it was concluded that the newly developed chemical WMA additve could be successfully used to produce the WMA mixture with the comparable performance to the HMA mixture. These laboratory evaluations should be confirmed by applying this additive to the field and monitoring the long-term performance of the pavement, which are scheduled in the near future.